Vehicle direct communication (VDC) means that vehicles directly communicate with each other by using a mobile communications device, for example, transfer information about a vehicle speed, location, driving direction, brake, and the like to each other.
In a motion process of vehicle user equipment (VUE), a size of a data packet for transferring a security assistance message between vehicles dynamically changes based on information such as a driving speed, an acceleration, and a direction, and a period also dynamically changes. Therefore, to reduce a transmission delay of the data packet and ensure packet delivery ratio (PDR) performance of the data packet, a base station needs to dynamically and flexibly schedule a time-frequency resource based on the size of the data packet.
Currently, device-to-device (D2D) communication of a Long Term Evolution (LTE) system supports a relatively small quantity of users, and when there are a relatively large quantity of VUEs, if D2D communication is used, a severe half-duplex collision in time domain and co-channel interference in frequency domain occur between different intra-cell VUEs and between different inter-cell VUEs, and an interference problem caused by severe in-band emission (IBE) occurs.